1. Field of the Invention
This invention pertains to the field of ammunition and explosives. More particularly it pertains to the field of arming devices incorporating a fluidic device.
2. Description of the Prior Art
It is well known to utilize fluidic oscillators to arm a weapon at a predetermined velocity thereof through the air, the oscillator being configured so as to be driven into oscillation by air flow at such velocity and an acousto-electrical of acousto-mechanical transducer being used to sense the oscillations. The use of fluidic oscillators or other devices sensing weapon velocity in this manner is advantageous in that the weapon not only does not arm until it attains such velocity but may be arranged to disarm when the velocity becomes less then such velocity, a feature particularly useful with an aircraft borne missile which should arm when the carrying aircraft is at flight speed and, preferably, should disarm automatically on landing if the aircraft returns with the missile unfired.
Insofar as known to the applicants, prior art fluid oscillators used for arming or disarming a weapon and driven by ram air require either an air inlet at the forward weapon end or a probe extended transversely of the weapon. Both of these arrangements present disadvantages with certain weapon configurations. One disadvantage is that such arrangements may not function properly at a high angle of attack. Another disadvantage is that a forward end inlet is inconvenient in a typical missile having its forward portion, devoted to guidance equipment and having an arming device located rearwardly in a warhead or a rocket motor which is directly controlled by the arming device and is usually stored separately from the guidance portion. Still another disadvantage is that transversely extended probes and elements of some forward inlets are commonly made retractable to save storage space and to avoid damage in handling. The arrangements required to provide for such retraction utilize space and weight which are at a premium in a missile.